1. Field of the Invention
The present invention relates to the field of rifles. The invention further relates to ejection ports for AR-15 and M-16 rifles. The invention even further relates to a safety and equipment protection a portion of an ejection port door that is impacted repetitively on its bumper. The present invention even further relates to a cover that removeably snaps upon the bumper of the ejection port door.
2. Description of Related Art
AR-15, AR-10 and M-15 rifles have been utilized for decades and are popular with civilians, law enforcement and military shooters around the world for the firearms' accuracy and modularity. In general such rifles are self-loading and capable of performing certain function without user assistance. When depressing the trigger, the rifle should fire a single cartridge, then extract the empty case from the chamber, eject the empty case, load another cartridge into the chamber from the magazine.
Two most common systems of are a direct impingement and indirect or gas impingement system. The direct impingement system reflects the original design by Stoner, as reflected in U.S. Pat. No. 2,951,424, for a gas operated bolt and carrier system, incorporated here by reference. Generally speaking, it routes exhaust gases from the barrel back through the rifle to move the bolt carrier to a retracted position, through the return tube to the bolt carrier and out the ejection port of the receiver.
With the more modern gas impingement system, as a projectile bullet fires it moves past a gas port located in the barrel of the firearm to convey gas into a port and through a gas tube and gas key. The high pressure gas then causes a bolt carrier to expand rearward and towards the butt of the firearm, as a result the bolt is unlocked from the barrel extension and carries rearward along with the bolt carrier. The bolt's rearward motion extracts an empty cartridge from the chamber. As the case clears the extension of the barrel, bolt's spring loaded ejector forces it from the ejection port in the side of the receiver.
With both systems, the ejection port often has an ejection port door that covers the ejection port to prevent debris from entering the receiver and interfering with firing components. The ejection port door automatically opens during the firing of the rifle, and is spring loaded to return to a closed position against the receiver after the empty case ejects from the port. The port door specifically contains a tab with a seating surface that forcefully returns against the door interface of the lower portion of the receiver. The seating surface is a small percentage of the entire surface area of the ejection port door. The forceful return of the ejection port door as created by the rearward action of the bolt creates a number of problems for the rifle, the operator and potentially others in the operator's party.
First, the forceful return of the ejection port door against the receiver is a highly impactful that degrades both the tab of the ejection port door as well as the receiver. As the gun undergoes repeated discharges, the tab and receiver will inevitably wear down to the point where they no longer interface correctly, causing operational failures much as misfiring, jamming, due to either an ejection port door that is sticks at the open/close position, or is unable to seat at either position. The operator must then attempt to replace the ejection port door and/or the portions of the receiver that meets the door. This is an involved, time and cost-consuming maintenance.
Second, the forceful return of the ejection port door against the receiver causes a loud report, as the door bumper and receiver are often made with metallic such as steel, aluminum or alloys thereof, or high-impact plastics. A loud report from the firearm can be detrimental from an array of tactical, environmental, and safety standpoints. It alerts others to the location of the operator and gives away the element of surprise, to for instance, a target of an ongoing tactical mission. A loud report may cause hearing injury, especially over time with repeated exposure. Such high-pitched pings may prevent the operator from collecting other, important auditory feedback from his or her environment. Finally, the loud report creates noise pollution that negatively impacts others nearby.
There is a need for a solution that reduces such loud reports from the use of such rifles. There is a need for better tactical outcomes when using rifles having ejection port doors. There exists a great need to reduce the noise pollution from the use of these rifles that is generated from the door striking the receiver. There further exists a need to prevent wear on parts of a rifle that are difficult to replace and maintain, where mechanical interactions between metal parts quickly degrade them.